Mains powered smoke alarms

Mains powered smoke alarms

Most properties in the UK have battery-operated smoke alarms, but mains powered smoke alarms interlinked between floors are the most reliable method of giving early warning in case of fire and must now be installed in all new homes.

Mains-wired smoke alarms are also required in certain types of alteration and extension work. Mount them in the circulation space at every floor level:

  • In loft conversions
  • When adding new habitable rooms (bedrooms, kitchens, living or dining rooms) above ground floor level
  • When adding a new habitable room at ground floor level that doesn’t have its own exit leading outdoors

Installing new interlinked smoke alarms can be disruptive, so think about the need for detection before you start work. Radio-linked alarms are acceptable; as long as the manufacturer can guarantee the battery back-up will last for 72 hours.

Smoke alarm DOs:

  • Ensure there’s at least one alarm on every storey of the dwelling
  • Ensure there’s an alarm within 7.5m of the door to every habitable room
  • Provide a heat detector to the kitchen if it’s open plan to the escape route
  • Mount them 300mm away from walls and light fittings
  • Ensure the electrical installation of the units meets Part P requirements
  • Provide instructions to the end user

Smoke alarm DON’Ts:

  • Install them above staircases where testing and maintenance is dangerous
  • Site them in places where they can become very hot, cold, or subject to a lot of moisture or fumes (bathrooms, kitchens, garages – use a heat detector if need be)

Remember, there are additional requirements for large houses of two or more storeys where one of those storeys exceeds 200m2, so bear this in mind when working on footballers’ mansions! If in any doubt, contact your local authority building control team to discuss.

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Mains powered smoke alarms

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